1. Field of the Invention
The present invention relates to a semiconductor processing method and a semiconductor structure, and particularly relates to a semiconductor processing method and a semiconductor structure that can adjust hole diameter via a single etching process.
2. Description of the Prior Art
In a semiconductor structure, a contact is utilized to contact metal and another feature. However, in some cases, the diameter of the same contact may need to be changed rather than remains constant. FIG. 1 is a schematic diagram illustrating a prior contact h. As shown in FIG. 1, the contact h0 is desired to contacts a target feature 101 but avoids contacting the non target feature 103. In order to manufacture such structure, a well controlled step forming the contact h0 such as an etching step is needed to generate a contact with accurate diameters. However, since the electronic device is getting tiny day by day, smaller diameter of the contact is needed thus the step of forming the contact h0 with desired diameter is getting harder to be controlled.
Besides, related skills may desire to reduce diameter of the contact when it is near the non target feature 103, as shown by the dotted line in FIG. 1. However, such process needs more steps than a normal process. For example, an first etching step is needed to form the part ha of the hole h0, which has a smaller diameter, then a second etching step is performed to form the part hb of the hole h, which has a larger diameter. These steps increase manufacturing time and are much harder to control than a normal process.